Such a ski brake is described for example in German OS No. 25 25 945. In this known construction, the axle on which the braking mandrels are arranged pivotally can, viewed in the longitudinal direction of said axle, be telescoped. Bent sections of the two braking mandrels, which extend below the pedal, are connected by means of a pin which can be also telescoped, and which pin is guided in turn in a slotted hole in a bar which is secured on the underside of the pedal, which slotted hole extends substantially parallel to the upper side of the pedal. The pedal has furthermore bars which point in direction toward the upper surface of the ski, which bars are arranged on the two sides of the pedal and have sloped surfaces on their inner sides, which sloped surfaces correspond each with a sloped surface of a cam which is associated with the individual braking mandrels. Furthermore a pressure spring can be utilized, which urges apart the two axial parts and to thus effect a lateral shifting of the braking mandrels as soon as the ski brake is in the braking position, namely the pedal is in the upwardly tilted position.
One disadvantage of this known ski brake lies in that through the closing of the pedal not only a swivelling of the braking mandrels, but also a shifting of the same transversely with respect to the longitudinal axis of the ski is to take place. Such a shifting can occur only when the braking mandrels lie already totally above the upper surface of the ski. Until this position is reached, however, the sloped area of each cam moves along the inner sloped surface of the two side bars of the pedal, so that the pulling-in effect occurs higher than desired. If this is supposed to be helped by the inner sloped surface of the two bars having a slope also extending in longitudinal direction of the ski, then the manufacture of this brake becomes more expensive and only the last sloped area remains in order to effect the so-called pulling in of the two braking mandrels above the upper surface of the ski. This manner of loading is not sufficient in order to be able to effect a fully effective pulling in.
A further disadvantage exists in that the bent sections require with the guide pin and the bar receiving said guide pin a structural height below the pedal, which dimensions increase, due to the here occurring forces, the entire structural height of the pedal in an undesired manner.
Finally it can also not be recognized through which force the pedal is to be swung from the ready or retracted position of the ski brake into the braking position of the latter, because the provided spring effects only a spreading-apart of the two braking mandrels. In the case of a stepped-down pedal with pulled-in braking mandrels, no force is created which would act vertically upwardly from the upper side of the ski. Should for this a separate spring be needed, then it is disadvantageous to use two springs, of which one effects an erecting of the brake and the other spring effects a spreading apart of the two braking mandrels.
Finally a separate axle which is arranged in a ski-fixed mounting is absolutely necessary for supporting the pedal. Disadvantageous is also the relatively great number of structural parts, their design and cooperation which takes place in several planes, which makes this brake not only expensive, but also susceptible to trouble. Since the braking mandrels are pressed by the spring which loads the axle constantly against the associated sloped surface of the relevant bar of the pedal, this contact force acts against the necessary swinging back of the braking mandrels from the ready position into the braking position. In order to be able to overcome this additional force, the erecting spring of the ski brake must be dimensioned stronger. This in turn has the result that the clamped-in ski boot is loaded with a greater force, than is the case in common ski brakes. This in turn has disadvantageous consequences for the release operations of the ski boot (danger of jamming).
If, however, the spring which loads the two axial parts should act also as an erecting spring, then the known solution is not serviceable, because in the stepped-down condition the cooperating sloped surfaces of bar and cam assume a position with one another in which the sloped surface of the cam is pivoted for approximately 90.degree., so that the sloped surface of the bar comes into contact with the cam of the braking mandrel only along one edge. Since due to the arrangement of the spring between these two sloped surfaces a contact is continuously needed, in the stepped-down condition of the pedal a shifting of the braking mandrels and a swinging of the pedal would have to be caused simultaneously, which movement due to the occurring friction is hardly possible. Thus a ski brake of the known type would remain in the swung-down position (self-locking). Therefore, it is not suited to safely stop a run-away ski.
The purpose of the invention is now to provide a ski brake of the above-mentioned type such that swinging and pulling-in of the braking mandrels takes place without the occurrence of the oppositely acting forces, and thus the use of a spring which produces the erecting force is sufficient. Thus, the inventive ski brake is to have a smaller number of structural parts compared with the conventional construction and these are also to be manufactured simpler. Also the structural height of the ski brake in the ready or retracted position is to be lower.
The set purpose is inventively attained by the axle for the braking wings or mandrels, as actually known, being supported in a ski-fixed holding plate, by each lever arm which extends from the axle in a direction toward the pedal having several bent sections, which are provided at least in the area of each braking wing or mandrel, which area is adjacent to the pedal and the bent sections which are associated with the pedal are arranged in pairs engaging slots which are provided in the underside of the pedal and of these pairs of bent sections, one is positioned substantially perpendicularly to the slot, in which it is guided and the further bent section which is connected to this bent section is arranged extending substantially parallel with respect to the underside of the pedal to guidingly secure the associated braking wing or mandrel against a falling out of the slot which guides said structural part.
Due to the inventive construction of the ski brake, the braking mandrels and also their axle can be manufactured of a wire material, whereby pulling-in is done by the cooperation of the bent areas of the individual braking wings or mandrels and the guideways which are associated therewith and are constructed as slots, which guideways are constructed in the underside of the pedal. The vertical arrangement of the end areas of the bent sections which face the pedal, which end areas act as guide pins with the slot, with which they are associated make a jamming impossible because the width dimension of the slot can be enlarged if necessary in the area in which the jamming could occur the easiest without altering the pulling-in effect. The inventive arrangement permits also a structural height of the entire ski brake which is lower with respect to the known solutions. The braking wings or mandrels will be identified hereinafter for the sake of simplicity only as braking wings or as braking mandrels. A preferable embodiment of the invention consists in the two braking wings being connected through openings which are provided in enlargements of said wings to each bent end of the axle and the enlargements of the braking wings are constructed preferably as shoulders which lie approximately perpendicularly with respect to the longitudinal axis, which shoulders form in the braking position of the ski brake with the bent ends of the axle an approximately right angle. This construction facilitates a specially simple support of the individual braking mandrels on the axle for the purpose of carrying out a swinging to effect a pulling thereof, only the area of the individual braking mandrels which is associated with the axle must be slightly flattened and enlarged.
A further thought of the invention consists in the two braking wings each having triple bent sections and each first bent section, viewed in a direction from the axle toward the pedal is constructed substantially extending at a right angle with respect to the longitudinal axis of the ski, each bent section which follows in the area of the slot is constructed pointing from the plane of the braking wings substantially normally toward the underside of the pedal and each third bent section is constructed extending approximately parallel to every first bent section. As a result, not only a secure guiding of the bent area of the individual braking mandrels, which area acts as a pin, is achieved but these are also secured against a falling out of the slot.
To arrange the spring which loads the ski brake, it is inventively provided that the one end of each spiral spring which swings the two braking wings into the braking position is suspended on the two third bent sections and the two other spring ends are suspended on an axis of rotation which is arranged in a ski-fixed mounting which extends parallel to the axis and lies at a distance from said axis in the ready position of the ski brake on the side which is remote from the pedal, and that the two springs are stored in a cavity of the pedal.
The degree of pulling in is determined by the course of the individual slots. It is inventively provided for this that the two slots starting at their ends which lie closer to the axes are constructed first in straight sections extending parallel with respect to the longitudinal axis of the ski and are subsequently bent toward (outwardly) the two edges of the ski, and that the length of the straight sections of the slots corresponds at least with the length difference, which is determined by the difference between the radius for pivoting the pedal about the axis of rotation which is associated with said pedal, or the two braking wings about the axis which is associated therewith.
According to a different embodiment of the invention, the mounting of the braking mandrels is constructed by the axle having one open eyelet at each of its two end areas, in which eyelets the two braking mandrels are arranged with each one being a conventional, approximately semicircular bend gripped around by the free end zones of the two eyelets and each form in this suspended position a bearing point with the two eyelets about which bearing point they are pivotal, controlled by the bent section of the respective slot, pointing toward the longitudinal direction of the ski or away from same. This construction facilitates a manufacture of the individual braking mandrels exclusively by bending same. By choosing the thickness of the wire material, from which the axle and the individual braking mandrels are made, also the size of the opening of the eyelet and the design of the approximately semicircular bend in the individual braking mandrels, the degree of the pulling in can thereby be determined.
A manner to hereby support the individual braking mandrels consists inventively in that, as is actually known, a pair of blind grooves is mounted on the part of the holding plate which lies remote from the axle, in the areas which are remote from the longitudinal axis of the ski and symmetrically to said longitudinal axis of the ski (on the two sides of the holding plate), and that a bent section of a guide member engages each blind groove, for which the blind groove serves as a guideway in the longitudinal direction of the ski and each guide member is hinged in a conventional manner at its end which is remote from the bent section to the associated braking wing.
A further development of the thought of the invention consists in that both on the individual braking wings and also on the guide members and substantially perpendicularly with respect to these structural parts, fastening pins are arranged for receiving each end of spiral springs which are arranged on said structural parts and which load the braking wings and the guide members in closing direction toward one another. This measure permits at the same time a symmetrical arrangement of two springs, which contributes additionally to an increase in stability of the entire construction.
A further thought of the invention consists in the pedal being hinged to the axis of rotation with the interpositioning of a connecting piece, which connecting piece with its end facing the pedal, is hinged to same by means of a connecting axle which extends through both the connecting piece and also the pedal substantially at a right angle with respect to the longitudinal axis of the ski, and in the connecting piece in the area of its two ends having preferably enlargements which extend perpendicularly with respect to the longitudinal axis of the ski. In this manner the angle for the pedal can be determined, so to speak, independently from the angle of the braking mandrels (both referred to the upper surface of the ski), through which the stepping-in comfort can be increased.
A still further thought of the invention consists in the pedal, as is actually known, being swingable relative to the braking wings or mandrels against the force of a leaf spring, which leaf spring is connected at one end to a ski-fixed fastening plate and at the other end to the pedal and the leaf spring is tensioned in the ready position of the ski brake and is relaxed to a slight amount of tension in the braking position. This design has the advantage that the brake is stabilized by the leaf spring in the direction which extends substantially at a right angle with respect to the longitudinal axis of the ski, without requiring additional guides, and for these separate guideways would be needed. The use of leaf spring permits also a position of the pedal which is independent of the angle of the braking mandrel in relationship to the upper surface of the ski, through which a comfortable stepping in is achieved.
This increased comfort is inventively assured by the underside of the pedal defining in the braking position of the ski brake with the upper surface of the ski or with the upper surface of the holding plate an angle of 15.degree. to 60.degree., preferably 30.degree. to 45.degree., in particular 40.degree., which upper surface is preferably a plane (so-called defining plane) which extends through the centerline of the axle and substantially parallel to the upper surface of the ski.
A particularly simple design of the slots consists advantageously in the grooves being constructed as a negative of an insert, preferably of plastic, which insert is inserted into the side of the pedal, which side faces the upper surface of the ski, and is secured possibly releasably on same or rather in same.
A further thought of the invention consists in the holding plate having a thick part for receiving the axle in the area where the braking mandrels are arranged, which axle is pivotally supported limited up to approximately 90.degree., preferably approximately at about 60.degree.. The thick part of the holding plate which serves as a bearing, preferably through the eyelets which are provided at the two free ends of the axle act as stops on the holding plate. Through this measure the desired braking position of the braking mandrels can be determined without using an additional stop.
For fastening the leaf spring on a fastening plate and on the pedal various measures can be taken. Also fixing of the fastening plate on the ski can be done in various manners. An advantageous inventive solution is that the leaf spring is fastened, for example riveted, to the fastening plate and/or to the pedal and on sloped surfaces on these structural parts, whereby the angle (.beta.) of the leaf spring, which is defined with the upper surface of the ski, is larger than the angle (.alpha.) which is defined by the pedal with the upper surface of the ski or with the upper surface of the holding plate or with the determining plane. In this type of fastening, the leaf spring may have a design extending in one single plane.
A modification of the type of fastening of the leaf spring consists inventively in the leaf spring being inserted in the fastening plate and/or in the pedal and having at least in the area of the fastening plate a bend, which angle (.alpha.) is the complementary angle to 180.degree. of the angle (.alpha.) which is defined by the leaf spring with the upper surface of the ski or with the upper surface of the base plate or with the determining plane. Through this design of the leaf spring, the initial tension of the same can be determined by the different slope of leaf springs or pedal and braking mandrels. This construction permits furthermore an inserting of the two free ends of the leaf spring into the fastening plate or into the pedal, which facilitates a parallel arrangement of this end area with respect to the upper and undersides of said holding parts. In this manner, fastening can occur by using increased frictional forces for example through an adhesive.
An inventive type of construction of the holding plate consists in the fastening plate for the leaf spring being constructed as a part of the holding plate which supports the ski-fixed axle of the braking mandrels. A different type of construction of the fastening plate consists in the fastening plate for the leaf spring being an attachment on the holding plate. The first mentioned type of construction of the fastening plate has the advantage that for fixing the fastening plate to the ski or to the holding plate no separate holding means are needed. The second embodiment, however, has the advantage that the position of the fastening plate in reference to the holding plate can be adjusted in the longitudinal direction of the ski, which permits the stepping-in angle of the pedal or the spacing of the area of the leaf spring which functions as a swivel axis for the pedal, from the axis of the braking mandrels, to be varied. Both types of construction of the fastening plate can be used for the aforedescribed types of the leaf spring; however, one will use the fastening plate which is constructed in one piece with the holding plate rather for a leaf spring which lies in one plane and the fastening plate which is constructed as an attachment for the leaf spring which has at least one bend therein.